Towards the end of the 19th century, a French art dealer called Ambroise Vollard ran a publishing business that was the only place to buy prints for up-and-coming young artists such as Pablo Picasso. The paper he used was distinctive, both in weight and texture: impossible to replicate.

Italian police would beg to differ. Over the past 12 months, in a Europe-wide investigation, detectives have uncovered an art forgery network that faked works by artists including Picasso, Edvard Munch and Paul Klee and distributed them in 23 countries. They used paper designed to appear as if it had come from Vollard’s vaults.

Italian authorities seized 104 fakes, said to be worth about $1.16 million.

The alleged con was based in the Tuscolano quarter of Rome with suspected accomplices around the world. Many of their methods were remarkably uncomplicated, detectives said: they were able to reproduce high-quality copies of original etchings by “aging” the paper by dipping it in coffee and tea. Authorities seized 104 of the forgeries, said to be worth about $1.16 million, and froze bank accounts containing almost $350,000.

“The suspects are Italians, one with a prior record for falsifying works of art,” said Lorenzo Galizia, a captain in the carabinieri squad specializing in art crime. “They didn’t create new works but copied already existing works that could be easily replicated because they were line drawings and not color paintings.”

The forgers used paper designed to appear as if it had come from Ambroise Vollard’s vaults.

Galizia said the forgers had produced plates that enabled them to make large numbers of prints with a technique similar to lithography. They sourced paper similar to that used by Vollard. “We were really struck by the reproductive skills of this gang. With the help of the printers they were able to reproduce a significant number of works and they were able to make them appear very close to the originals, to the point of duping the auction houses that they dealt with,” Galizia told The Times.

“If their behavior had not been stopped it would certainly have led to huge economic damage to the buyers,” he added.

The Italian authorities have been investigating distribution channels in 13 EU countries and nine countries outside the bloc, including the US and the UK. Galizia said that five auction houses in the UK had acquired works from the forgers and the works had been seized there by investigators. “We don’t know whether or not the auction houses had realized they were fakes. They were probably acting in good faith,” he said.

“The Italian forgers didn’t create new works but copied already existing works that could be easily replicated.”

This is just the latest in a spate of art forgeries discovered by Italian police, with Picasso one of the favorites for reproduction. In February the art police announced the discovery of a forgery workshop in Rome producing works attributed to Picasso and Rembrandt as well as to numerous lesser known modern artists. Some were being offered for sale on websites such as eBay and Catawiki and a total of 71 fakes were seized.

Last November prosecutors in Pisa said they were investigating 38 people for suspected membership of a pan-European forgery network making and selling art works attributed to Picasso, Banksy and Andy Warhol.

On that occasion they said they had discovered six forgery workshops, three in Italy and the others in the rest of Europe. To boost their credentials, the suspects organized two Banksy exhibitions with a published catalog, in prestigious locations in Mestre near Venice and Cortona in Tuscany.

The pan-European forgery network’s collection includes forgeries of works by Picasso, Banksy, and others.

A year ago it emerged that Picasso had suffered the indignity of having his works faked and displayed in the ladies’ lavatory of a museum in Tasmania.

The prank was the work of the artist Kirsha Kaechele, the wife of the owner of Tasmania’s Museum of Old and New Art (Mona). Kaechele apologized and admitted she had painted the works herself with help from her “manicurist’s niece”.

There has been a healthy growth in Italy’s legal art market in recent years, with new art galleries opening in its major cities. The sector received a boost in June when the government reduced the rate of VAT from 22 percent to 5 percent, the lowest level in the EU. The economic think tank Nomisma said the measure could increase earnings for the sector from an annual $1.5 billion to $1.75 billion per quarter.

Philip Willan is a British journalist based in Rome